The groups claim the commission and Encana, are in violation of the province's century-year-old Water Act because of the repeated use of short-term permits allowing millions of litres of fresh water to be drained from lakes, streams and rivers and mixed with chemicals and sand and injected under high pressure into the ground to release natural gas.

Morgan Blakley, a lawyer who represents the coalition, says his clients believe repeatedly granting short-term water withdrawal permits to the same company for the same reason is illegal.

"The commission grants short-term water rights to oil and gas companies over and over again," he said. "If these oil and gas companies want water for more than two years they have to get a water licence."

The coalition alleges that the commission has repeatedly granted the energy company short-term approvals, with the earliest starting from December 2006 and the latest ending in May 2014, and is asking the court to rescind several short-term approvals the commission has issued to Encana.

But Encana spokesman Jay Averill says what the company is doing is legal.

"Encana believes there is no proper basis to quash the subject approvals given the proper interpretation of Section 8 of the Water Act," he wrote in an email statement.

The Oil and Gas Commission sent CBC a statement saying all water applications go through a review process and declined comment on the lawsuit, citing the fact the case is before the courts.

Section 8 of the Water Act states:

"Short term use of water: 8 (1) If diversion or use of water is required for a term not exceeding 24 months, the comptroller or a regional water manager may, on application, without issuing a licence, grant an approval in writing, approving the diversion or use, or both, of the water on the conditions the comptroller or regional water manager considers advisable."